Bulk email software

Our company develops some activities in the field of email marketing and his willing to build its own bulk email solution competing with solutions such as MailChimp, Bulkresponse, etc. We are looking for experienced persons with a deep knowledge of the email marketing infrastructure and some experience with a leading exisiting emailing solution or a large similar project. The system should be well designed and scalable to deliver any number of emails from 1 to 100 millions per month with a quasi constant time to execute the campaign. Of course deliverability will be a key points to implement . Please contact us if you have the requested level and skills and let us know how you could partcipate (architect, developer, UI/UX designer, etc.) as well as some information about the budget requested.